简介:摘要:随着农业生产机械化发展,越来越多的农户都能享受到机械种植所带来的便利。就我区最为常见的水稻种植来说,目前水稻机插秧已逐年被种植大户和普通农民接受,面积不断扩大,已成为水稻的主要移栽方式。由于水稻立枯病造成死苗、缺苗、大田返青慢、生育期延长,已成为制约水稻机插秧的主要因素。
简介:EighteenisolatesofRhizoctoniasolanicollectedfrominfectedriceplantsinfourdifferentlocationsofBangladeshwerestudiedbyusingmorphologicalcharactersandmolecularmarkers.AnastomosisstudywithareferenceisolateconfirmedthatalltheisolatesbelongedtoR.solani.Significantvariationwasobservedinsclerotialsize,shapeanddistribution.Un-weightedpairgroupmethodwitharithmeticmeandendrogramconstructedbasedontheGower’sgeneralsimilaritycoefficientshowedthattheseisolatesweregroupedintofourclustersatthe0.68similaritycoefficentaccordingtomorphologicalcharacters.ClusterIwasamajorclusterconsistingof13isolates,whileclustersⅡtoⅣconsistedof1or2isolates.Analysesbyvariablenumberoftandemrepeatandamplifiedfragmentlengthpolymorphismmarkersshowedthattheisolatesweregroupedintofiveandthreeclustersatasimilaritycoefficientof0.64and0.69,respectively.Althoughmostofthevariabilitywasfoundbetweenisolatesfromdifferentregionsasexpected,significantvariationwasobservedwithintheisolatescollectedfromsimilaragro-ecologicalregions.OurresultssuggestthepresenceofdifferentracesofR.solaniwithinthesamelocalgeographicregions.
简介:solani孤立的Rhizoctonia的55件代表性的样品,从在四川省的五个不同生态的区域镇定、孤立,中国,为致病力和分子的基因变化被净化并且分析。菌丝的熔化测试表明除了isolateD42,几乎所有isolates属于AG-IIA组。另外,一些isolates正在衔接孤立,它能同时与几熔化组。致病力分析在上在vitro,叶子证实了一个重要致病力变化在测试孤立。55孤立然后被进一步的RAPD(随机放大的多态的DNA)分类进8个组在0.941的类似系数的簇分析。结果在四川省在某些生态的条件下面建议那,中国,大多数R。solani紧张是遗传上稳定的,但是一些急速地变化了。